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Abstract:

The present application provides a method and a device for saving network
resources, wherein the method particularly includes: determining that a
user equipment has the property of small data amount transfer; and during
network attachment, allocating no user plane resources to the user
equipment which has the property of small data amount transfer. The
present application is used to save network resources in an LTE system
during M2M communication.

Claims:

1. A method for saving a network resource, comprising: determining that a
user equipment has a characteristic of small data transmission; and
allocating no user plane resource to the user equipment with the
characteristic of small data transmission in a network attachment
procedure.

2. The method of claim 1, wherein determining that a user equipment has a
characteristic of small data transmission comprises: determining from a
request message transmitted from the user equipment that the user
equipment has the characteristic of small data transmission; or
determining that the user equipment has the characteristic of small data
transmission upon determining from subscription data of the user
equipment that the user equipment has subscribed for the characteristic
of small data transmission.

3. The method of claim 2, wherein the request message is an Attach
Request message; and the Attach Request message carries an indicator of
the characteristic of small data transmission to indicate that the user
equipment has the characteristic of small data transmission; or the
Attach Request message carries no Packet Data Network, PDN, connection
establishment request message to indicate implicitly that the user
equipment has the characteristic of small data transmission.

4. The method of claim 3, wherein the indicator of the characteristic of
small data transmission includes any one or combination of the following
information elements: a newly added EPS Attach Type, a newly added
Request Type or a newly added Access Point Name.

5. The method of claim 1, wherein allocating no user plane resource to
the user equipment with the characteristic of small data transmission
comprises: in the network attachment procedure, establishing no Packet
Data Network, PDN, connection for the user equipment with the
characteristic of small data transmission; or establishing for the user
equipment with the characteristic of small data transmission a PDN
connection to which no user plane resource is required to be allocated.

6. The method of claim 5, wherein establishing a PDN connection to which
no user plane resource is required to be allocated comprises: allocating
a null resource to the PDN connection and transmitting a Create Session
Request message carrying an indicator of no bearer being required to be
established to instruct a Serving Gateway, SGW, to allocate a null
resource to the PDN connection.

7. The method of claim 1, further comprising: transmitting a message
carrying an indicator of a null resource for the user equipment to an eNB
to instruct the eNB not to allocate any user plane resource to the user
equipment.

8. The method of claim 1, further comprising: making a record
corresponding to bearer allocation to the user equipment in a context of
the user equipment upon reception of an Update Location Request message
transmitted from a Home Subscriber Server, HSS.

9. The method of claim 8, wherein making a record corresponding to bearer
allocation to the user equipment in a context of the user equipment
comprises: creating no context of any PDN connection and preserving a
mobility management context, in the context of the user equipment; or
including a flag bit in the context of the user equipment to indicate
that no PDN connection is established for the user equipment and setting
the flag bit; or including a flag bit in the context of the user
equipment to indicate that a PDN connection is established but no bearer
is established for the user equipment and setting the flag bit.

10.-12. (canceled)

13. A method for saving a network resource, comprising: an evolved Node
B, eNB, receiving an indicator of a null resource transmitted from a
Mobility Management Entity, MME, for a user equipment with a
characteristic of small data transmission; and the eNB allocating no user
plane resource to the user equipment.

14. An apparatus for saving a network resource, comprising: an obtaining
module configured to determine that a user equipment has a characteristic
of small data transmission; and an bearer allocating module configured to
allocate no user plane resource to the user equipment with the
characteristic of small data transmission in a network attachment
procedure.

15. The apparatus of claim 14, wherein the obtaining module is
particularly configured to determine from a request message transmitted
from the user equipment that the user equipment has the characteristic of
small data transmission; or to determine that the user equipment has the
characteristic of small data transmission upon determining from
subscription data of the user equipment that the user equipment has
subscribed for the characteristic of small data transmission.

16. The apparatus of claim 15, wherein the request message is
particularly an Attach Request message; and the Attach Request message
carries an indicator of the characteristic of small data transmission to
indicate that the user equipment has the characteristic of small data
transmission; or the Attach Request message carries no PDN connection
establishment request message to indicate implicitly that the user
equipment has the characteristic of small data transmission.

17. The apparatus of claim 16, wherein the indicator of the
characteristic of small data transmission includes any one or combination
of the following information elements: a newly added EPS Attach Type, a
newly added Request Type or a newly added Access Point Name.

18. The apparatus of claim 14, wherein the bearer allocating module is
particularly configured, in the network attachment procedure, to
establish no Packet Data Network, PDN, connection for the user equipment
with the characteristic of small data transmission; or to establishing
for the user equipment with the characteristic of small data transmission
a PDN connection to which no user plane resource is required to be
allocated.

19. The apparatus of claim 18, wherein the bearer allocating module is
configured to establish a PDN connection to which no user plane resource
is required to be allocated by: allocating a null resource to the PDN
connection and transmitting a Create Session Request message carrying an
indicator of no bearer being required to be established to instruct a
Serving Gateway, SGW, to allocate a null resource to the PDN connection.

20. The apparatus of claim 14, further comprising: a null resource
indicator carrying module configured to transmit a message carrying an
indicator of a null resource for the user equipment to an eNB to instruct
the eNB not to allocate any user plane resource to the user equipment.

21. The apparatus of claim 14, further comprising: a recording module
configured to make a record corresponding to bearer allocation to the
user equipment in a context of the user equipment upon reception of an
Update Location Request message transmitted from an HSS; and wherein the
recording module is configured to make a record corresponding to bearer
allocation to the user equipment in a context of the user equipment by:
creating no context of any PDN connection and preserving a mobility
management context, in the context of the user equipment; or including a
flag bit in the context of the user equipment to indicate that no PDN
connection is established for the user equipment and setting the flag
bit; or including a flag bit in the context of the user equipment to
indicate that a PDN connection is established but no bearer is
established for the user equipment and setting the flag bit.

22. (canceled)

23. The apparatus of claim 14, wherein the apparatus for saving a network
resource is a Mobility Management Entity, MME.

24.-26. (canceled)

27. An evolved Node B, comprising: an indicator receiving module
configured to receive an indicator of a null resource transmitted from a
Mobility Management Entity, MME, for a user equipment with a
characteristic of small data transmission; and a null resource allocating
module configured to allocate no user plane resource to the user
equipment.

Description:

[0001] This application claims the benefit of Chinese Patent Application
No. 201010527247.0, filed with the Chinese Patent Office on Oct. 26, 2011
and entitled "Method and system for saving network resource", which is
hereby incorporated by reference in its entirety.

FIELD

[0002] The present invention relates to the field of communication
technologies and particularly to a method and apparatus for saving a
network resource.

BACKGROUND

[0003] A characteristic in the 3rd Generation Partnership Project
(3GPP) Machine to Machine (M2M) communication specification is small data
transmission, for example, it is only necessary to transfer small amount
of data between a Machine Type Communication (MTC) terminal and an MTC
server.

[0004] In view of this characteristic of small data transmission, existing
network optimization methods are as follows:

[0005] A1. The small data is transferred in a short message, where the
short message can be transferred via an SGs interface between a Mobility
Management Entity (MME) and a Mobile Switching Center (MSC)/a Visitor
Location Register (VLR); and

[0006] A2. Data is transmitted along with a signalling message to an
MME/SGSN (Serving GPRS Support Node) or other mobility management
entities, and the MME/SGSN forwards the data directly to an MTC server,
and at this time a new interface will be introduced between the MME/SGSN
and the MTC server.

[0007] In a Long Term Evolution (LTE) system, a User Equipment (UE) has to
establish its Packet Data Network (PDN) connection to a default Access
Point Name (APN) in an attach-to-network procedure. Resources of network
nodes, e.g., resources at an evolved Node B (eNB), an MME, a Serving
Gateway (SGW), a Packet Data Network (PDN) Gateway (PGW), etc., will be
occupied after this PDN connection is established. These resources
generally include a storage resource at a network node, the identifier of
a tunnel of a user plane connection and other user plane resources. The
LTE system is designed as such from the perspective of the characteristic
of "Always-On" to ensure that the UE can establish a connection required
for communication so long as the UE is attached to the LTE network, so a
user can communication conveniently and rapidly.

[0008] Since the small amount of data is transmitted along with a
signalling message, i.e., on a signalling plane, in both of the foregoing
methods A1 and A2, the small data is transmitted without using any user
plane resource. In view of such a characteristic that there are a very
large number of MTC terminals in M2M communication and transmission of
only small data is required for the majority of the MTC terminals, a
considerable waste of network resources will inevitably result if PDN
connections are established for the large number of MTC terminals on the
LTE network but are not used in practical communication.

[0009] In general, it is highly desirable for those skilled in the art to
address a technical problem of how to alleviate a waste of network
resources under the foregoing circumstance.

SUMMARY

[0010] An aspect of the invention is to provide a method and apparatus for
saving a network resource so as to save a network resource in M2M
communication of an LTE system.

[0011] In order to address the foregoing problem, the invention discloses
a method for saving a network resource, which includes:

[0012] determining that a user equipment has the characteristic of small
data transmission; and

[0013] allocating no user plane resource to the user equipment with the
characteristic of small data transmission in a network attachment
procedure.

[0014] The invention further provides another method for saving a network
resource, which includes:

[0015] a Serving Gateway, SGW, receiving an indicator, of no bearer being
required to be established, from a Mobility Management Entity, MME, for a
user equipment with the characteristic of small data transmission; and

[0016] the SGW allocating a null resource to a Packet Data Network, PDN,
connection and transmitting a Create Session Request message, carrying
the indicator of no bearer being required to be established, to a Packet
Data Gateway, PGW, to instruct the PGW to allocate a null resource to the
PDN connection.

[0017] The invention further provides another method for saving a network
resource, which includes:

[0018] a Packet Data Gateway, PGW, receiving an indicator, of no bearer
being required to be established, transmitted from a Serving Gateway,
SGW, for a user equipment with the characteristic of small data
transmission; and

[0019] the PGW allocating a null resource to a Packet Data Network, PDN,
connection and returning a Create Session Response message to the SGW.

[0020] The invention further provides another method for saving a network
resource, which includes:

[0021] an evolved Node B, eNB, receiving an indicator of a null resource
transmitted from a Mobility Management Entity, MME, for a user equipment
with the characteristic of small data transmission; and

[0022] the eNB allocating no user plane resource to the user equipment.

[0023] The invention has the following advantages over the prior art:

[0024] With the invention, no user plane resource is allocated to a user
equipment with the characteristic of small data transmission in a network
attachment procedure; and there are a large number of user equipments
with the characteristic of small data transmission in 3GPP M2M
commutation, so the invention can significantly save user plane resources
to thereby enable a larger number of user equipments to access a network.

BRIEF DESCRIPTION OF THE DRAWINGS

[0025] FIG. 1 is a flow chart of a first embodiment of a method for saving
a network resource according to the invention;

[0026] FIG. 2 is a flow chart of a second embodiment of a method for
saving a network resource according to the invention;

[0027] FIG. 3 is a flow chart of a third embodiment of a method for saving
a network resource according to the invention;

[0028] FIG. 4 is a flow chart of a fourth embodiment of a method for
saving a network resource according to the invention;

[0029] FIG. 5 is a flow chart of a fifth embodiment of a method for saving
a network resource according to the invention; and

[0030] FIG. 6 is a schematic structural diagram of an embodiment of a
system for saving a network resource according to the invention.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0031] The invention will be further described in details below with
reference to the drawings and embodiments thereof in order to make the
foregoing aspect, features and advantages of the invention become more
apparent.

[0032] A core idea of the embodiments of the invention lies in that no
user plane resource is allocated to a user equipment with the
characteristic of small data transmission in a network attachment
procedure to thereby save a network resource, thus enabling a larger
number of user equipments to access a network.

[0033] Referring to FIG. 1 illustrating a flow chart of a first embodiment
of a method for saving a network resource according to the invention, the
method may particularly include:

[0034] an operation 101 to determine that a user equipment has the
characteristic of small data transmission.

[0035] The invention can be applicable to M2M communication of an LTE
system in order to accommodate the characteristic of small data
transmission of the user equipment on the precondition of saving a
network resource.

[0036] In practice, the user equipment may be a UE, an MTC terminal, etc.,
and the invention will not be limited to any specific user equipment. The
following description will be given taking a UE as an example and can
also apply to other user equipments.

[0037] For a UE which has subscribed for only the characteristic of small
data transmission, it can be known directly from subscription data of the
UE that the UE has subscribed for the characteristic of small data
transmission, and thus it is determined that the UE has the
characteristic of small data transmission. In practice, a Home Subscriber
Server (HSS) generally stores the subscription data of the UE.

[0038] However numerous UEs have subscribed for both the characteristic of
small data transmission and another characteristic or characteristics
which may include a resource characteristic of setting up a PDN
connection, for example, the characteristic of Packet Service Only (PS
Only). At this time which characteristic is currently used by the UE and
thus whether the UE uses the characteristic of small data transmission is
unknown to a network.

[0039] In view of the foregoing circumstance, it can be determined, from a
request message transmitted from the user equipment, that the user
equipment has the characteristic of small data transmission in a
preferred embodiment of the invention.

[0040] In a specific implementation, an indicator of the characteristic of
small data transmission can be carried in an Attach Request message
transmitted from the user equipment to indicate that the user equipment
has the characteristic of small data transmission; and then it is known
from the indicator of the characteristic of small data transmission that
the user equipment has the characteristic of small data transmission.

[0041] As an implementation scheme, the indicator of the characteristic of
small data transmission may include any one or more of the following
Information Elements (IEs): a newly added EPS Attach Type, a newly added
Request Type or a newly added Access Point Name (APN).

[0042] For example, the newly added Request Type can be given a new value
MTC-Low-Data-Request so that an MME can determine from the new value that
the UE has the characteristic of small data transmission.

[0043] As another implementation scheme, the presence of the
characteristic of small data transmission can be indicated implicitly to
the network in the Attach Request message in which no PDN connection
establishment request message is carried.

[0044] Typically the UE will transmit a first Non-Access Stratum (NAS)
message including two messages to the network in a network attachment
procedure, where one is an Attach message and the other is a PDN
connection establishment request message (PDN Connectivity Request), and
the PDN connection establishment request is carried along with the
transmitted Attach message.

[0045] In summary the inventors of the invention have innovatively
proposed that the user equipment transmits a first NAS message including
only one message, i.e., an Attach message, but carrying no PDN connection
establishment request message to the network when the UE has the
characteristic of small data transmission. Thus the MME can know that the
user equipment has the characteristic of small data transmission.

[0046] As can be appreciated, those skilled in the art can use the several
schemes to determine that the user equipment has the characteristic of
small data transmission in combination or use any one of the schemes as
needed. Furthermore those skilled in the art can further use other
schemes in addition to the foregoing several schemes, and the invention
will not be limited in this regard.

[0047] The method includes an operation 102 to allocate no user plane
resource to the user equipment with the characteristic of small data
transmission in a network attachment procedure.

[0048] No user plane resource may be allocated to the user equipment at
the network side upon knowledge of that the user equipment has the
characteristic of small data transmission for the purpose of saving a
network resource.

[0049] The invention may provide the following schemes to allocate no user
plane resource to the user equipment:

[0050] First Scheme

[0051] No PDN connection is established for the user equipment with the
characteristic of small data transmission in the network attachment
procedure.

[0052] In practice, the MME can skip the operation of setting up a PDN
connection in the existing network attachment procedure if the MME knows
that the user equipment has the characteristic of small data
transmission. Since no PDN connection is established, no user plane
resource will be allocated to the user equipment, and thus a user plane
network resource can be saved and also a signalling resource used for a
PDN connection can be saved.

[0053] Second Scheme

[0054] A PDN connection, to which no user plane resource is required to be
allocated, is established for the user equipment in the network
attachment procedure.

[0055] This scheme may be performed in the following sub-operations:

[0056] A sub-operation A1 is to transmit from the MME a Create Session
Request message carrying an indicator of no bearer being required to be
established to instruct a Serving Gateway (SGW) and a Packet Data Gateway
(PGW) to allocate a null resource to a PDN connection; and

[0057] Upon knowledge of that the user equipment has the characteristic of
small data transmission, the MME stills performs a PDN connection
establishment procedure and carries the indicator of no bearer being
required to be established in a relevant Create Session Request message
to indicate that no resource for transmission of data is required to be
reserved for the PDN connection.

[0058] In a sub-operation A2, the SGW and the PGW allocate a null resource
to the PDN connection according to the indicator of no bearer being
required to be established.

[0059] In a subsequent PDN connection establishment procedure, the SGW,
the PGW (Packet Data Network-Gateway) and other network nodes may perform
a necessary process according to this indicator but will not reserve for
the PDN establishment any resource for transmission of user plane data.
The sub-operation A2 may particularly include:

[0060] An operation A21, the SGW receives the Create Session Request
message transmitted from the MME, allocates a null resource to the PDN
connection according to the indicator of no bearer being required to be
established in the message and transmits a corresponding Create Session
Request message to the PGW while carrying the indicator of no bearer
being required to be established in the corresponding message;

[0061] An operation A22, the PGW allocates a null resource to the PDN
connection according to the Create Session Request message received from
the SGW and returns a corresponding Create Session Response message to
the SGW; and

[0062] An operation A23, the SGW returns a corresponding Create Session
Response message to the MME according to the Create Session Response
message from the PGW.

[0063] In the foregoing operations, the MME, the SGW and the PGW will
create information of a context for the PDN connection and allocate a
resource according to an existing solution. However in the method
according to the invention, it is not necessary to establish a
bearer-related resource for the UE, so it is only necessary to identify
that no resource required for the PDN connection is allocated to the UE.
One approach is to create no context of the PDN connection but to include
a flag to indicate that no PDN connection is established for the UE, and
another approach is to create a context of the PDN connection but also
indicate that this context is a null context, that is, all the entries in
the context are null, to thereby indicate that a null resource is
allocated for the PDN connection. This method will not preclude other
approaches for identifying that a network node allocates no resource to
the UE.

[0064] As can be appreciated, those skilled in the art can use the
foregoing two schemes in combination or use any one of the schemes as
needed, and the invention will not be limited in this regard. For
example, only the MME will be modified in behavior to perform the first
scheme at the network side, but the SGW and the PGW will further be
modified in behavior to perform the second scheme, so the first scheme
will be adopted to save the behavior modification.

[0065] A large number of user equipments will have the characteristic of
small data transmission for the purpose of an optimized network in 3GPP
M2M communication, and since the invention will not allocate any user
plane resource to the large number of user equipments, user plane
resources can be saved significantly, and thus a larger number of user
equipments can be enable to access the network.

[0066] Since no PDN connection is established in the first scheme and no
user plane resource is allocated for a PDN connection, it is not
necessary to allocate any user plane resource to the PDN connection at
the network side. Thus in a preferred embodiment of the invention, an
indicator of a null resource corresponding to the user equipment can be
carried in an Initial Context Setup Request message transmitted from the
MME to an eNB to instruct the eNB not to allocate any user plane resource
to the user equipment.

[0067] In a specific implementation, for an E-UTRAN Radio Access Bearer to
Be Setup List (E-RAB to Be Setup List) of the Initial Context Setup
Request message:

[0068] a) an indicator of a "Null Resource" can be defined in the list,
and thus the eNB will not establish any radio resource; for example, a
special E-RAB ID can be defined, and the eNB will understand that no user
plane resource is required to be established if the E-RAB ID takes the
value of 0.

[0069] b) the list can be set to include no item Information Element (IE)
of any E-RAB to Be Setup, and at this time, the eNB can also understand
that no user plane resource is required to be established.

[0070] Of course, those skilled in the art can further define other
indicator of a null resource or include a defined indicator of a null
resource in an Attach Accept message under practical circumstances, and
the invention will not be limited in this regard.

[0071] In the prior art, if the UE moves from an old location to a new
location (for example, the UE moves out of a location area where it is
registered) after the UE is attached to the network, then its mobility
management entity will possibly be changed from an old MME to a new MME
and a Track Area Update (TAU) procedure will be triggered. A TAU
procedure in the case that no PDN connection is established in the
invention will be described blow.

[0072] In another preferred embodiment of the invention, the method for
saving a network resource may further include:

[0073] the MME makes a record corresponding to bearer allocation to the
user equipment in the context of the UE upon reception of an Update
Location Request message from a Home Subscriber Server (HSS).

[0074] In practice, the record can be made according to the type of bearer
allocation to the user equipment.

[0075] The following process is performed for the type of no PDN
connection to be established:

[0076] at this time, no context of any PDN connection is created and only
a mobility management context is preserved, in a context of the UE; or a
flag bit, e.g., the existing flag of the small data attribute or a flag
of whether to establish a PDN connection, is included in the context of
the UE and is set. Thus a new MME can know form the context of the UE
that the old MME sets up no PDN connection for the UE.

[0077] The following process is performed for the type of a PDN connection
to be established to which no user plane resource is required to be
allocated:

[0078] at this time, a flag bit, e.g., the No-EPS-Bearer-Established-Flag,
can be included in the context of the UE and can be set. Thus the new MME
can know form the context of the UE that the old MME sets up no bearer
for the UE although it sets up a PDN connection for the UE.

[0079] Information of the record can be transferred from the old MME to
the new MME in the TAU procedure, and then, the new MME can perform the
PDN connection and TAU procedure of the UE according to the context of
the UE from the old MME.

[0080] Embodiments of the foregoing solution will be provided below to
make those skilled in the art better understand the invention:

[0081] Referring to FIG. 2 illustrating a flow chart of a second
embodiment of a method for saving a network resource according to the
invention, the method may particularly includes:

[0083] Referring to Table 1, the EPS Attach Type can be encoded with one
byte in an application instance of the invention, where the value of the
EPS Attach Type is represented in lower three bits (321). Referring to
Table 2, the newly added MTC-Low-Data Attach can be represented as 101 in
an embodiment of the invention.

[0084] Referring to Table 3, the Request Type can be encoded with one byte
in another application instance of the invention, where the value of the
Request Type is represented in lower three bits (321). Referring to Table
4, the newly added MTC-Low-Data Request can be represented as 101 in an
embodiment of the invention.

[0085] As can be appreciated, those skilled in the art can select any one
or combination of the foregoing two newly added types as needed in
practice.

[0086] For example, if the UE transmits small data in a short message,
then the value of the EPS Attach Type can be set to Combined EPS/IMSI
Attach and the value of the Request Type can be set to MTC-Low-Data
Request.

[0087] In another example, if the UE transmits small data on a signalling
connection of an EPS system instead of transmitting the small data in a
short message, then the value of the Request Type shall be set to
MTC-Low-Data Request. At this time, the value of the EPS Attach Type can
be set to MTC-Low-Data Attach.

[0088] Operation 202, an MME knows from the value or values of the EPS
Attach Type and/or the Request Type that the UE has the characteristic of
small data transmission upon reception of the Attach Request message;

[0089] Operation 203, the MME skips the operation of setting up a PDN
connection in the existing network attachment procedure upon reception of
an Update Location Request transmitted from an HSS;

[0090] Operation 204, the MME carries an indicator of a null resource
corresponding to the user equipment in an Initial Context Setup Request
message transmitted to an eNB; and

[0091] Operation 205, the eNB allocates no user plane resource to the user
equipment and transmits an Attach Complete message to the MME.

[0092] The operation of setting up a PDN connection and the operation of
updating a bearer of the network to which the UE is attached in the
existing network attachment procedure are omitted in this embodiment, and
thus a signalling resource in addition to a user plane resource can be
further saved.

[0093] In the prior art, a Tracking Area Update (TAU) procedure will be
triggered if the UE moves from an old MME to a new MME after the UE is
attached to the network, and a TAU procedure in the case that no PDN
connection is established in the invention will be described below.

[0094] In a preferred embodiment of the invention, the method for saving a
network resource may further include:

[0095] Operation B1, the MME makes a record corresponding to bearer
allocation to the user equipment in a context of the UE upon reception of
an Update Location Request message from the HSS;

[0096] Operation B2, the old MME returns the corresponding context of the
UE upon reception of a Context Request message of the UE from the new
MME; and

[0097] Operation B3, the new MME determines from the corresponding record
in the context of the UE that the old MME establishes no PDN connection
for the UE and then skips TAU and PDN connection processes of the UE.

[0098] Since the TAU and PDN connection processes of the UE can be skipped
according to information of the record, a signalling resource in the TAU
procedure can be saved.

[0099] It shall be noted that this preferred embodiment will not be
limited to the second embodiment but can be applicable to any network
attachment, TAU and other procedures in the case that no PDN connection
is established.

[0100] Referring to FIG. 3 illustrating a flow chart of a third embodiment
of method for saving a network resource, the method may particularly
include:

[0102] Operation 302, an MME knows from the value or values of the EPS
Attach Type and/or the Request Type that the UE has the characteristic of
small data transmission upon reception of the Attach Request message;

[0103] Operation 303, the MME transmits a Create Session Request message
to an SGW while carrying an indicator of no bearer being required to be
established in the message;

[0104] In an application instance of the invention, the indicator of no
bearer being required to be established can be filled into the
information element of Indication Flags in the Create Session Request
message; for example, an indicator No_Bearer_Flag can be defined and set
to 1 when no bearer is required to be established.

[0105] Alternatively in an application instance of the invention, a "Null
Resource" can be defined, in the information element of Bearer Context to
be created, to specify information on a bearer to be established for the
PDN connection. Specifically a "Null Resource" can be represented as a
special EPS Bearer ID. For example, the value of the EPS Bearer ID
currently ranges from 5 to 15, and thus a "Null Resource" can be
represented as any value ranging from 1 to 4.

[0106] In this instance, a "Null Resource" can be indicated by modifying
other fields, and the invention will not be limited to any specific
indicator of a "Null Resource".

[0107] Operation 304, the SGW allocates no user plane resource to the UE
according to the indicator of no bearer being required to be established
and transmits a corresponding Create Session Request message to a PGW
while carrying the indicator of no bearer being required to be
established in the message.

[0108] Since it is not necessary for the SGW to allocate any resource to
the UE, the SGW can set the Serving GW Address for the User Plane, the
Serving GW TEID of the User Plane and the EPS Bearer Identity, in the
Create Session Request message transmitted from the SGW to the PGW, to
special values, for example, these values may not point to any resource
or they may point to a null resource. Specifically the Serving GW Address
for the User Plane can be set to 0.0.0.0; the Serving GW TEID of the User
Plane can be set to 0; and the EPS Bearer Identity can be set to a
special value (e.g., 0). Also the SGW will further transmit the received
indicator of no bearer being required to be established (e.g., No PDN
Flag) as well to the PGW.

[0109] Operation 305, the PGW allocates no user plane resource to the UE
according to the Create Session Request message and returns a
corresponding Create Session Response message to the SGW.

[0110] The PGW determines from the received message that no user plane
resource is required to be established for the UE and thus will set
correspondingly the Create Session Response message returned to the SGW.
Specifically, the PDN GW Address for the User Plane can be set to
0.0.0.0, and the PDG GW TEID of the User Plane can be set to 0.

[0111] At this time, no user plane resource is established, so the other
relevant parameters, e.g., the EPS Bearer Quality of Service (QoS), the
Protocol Configuration Options, the Payload Compression, the APN
Restriction, etc., may not be set anyway; and furthermore it is not
necessary for the PGW to take into account the parameters of PDN Type,
Dual Address Bearer Flag, etc., in the message.

[0112] Operation 306, the SGW returns a corresponding Create Session
Response message to the MME according to the Create Session Response
message from the PGW;

[0113] The SGW shall return a Create Session Response message to the MME
upon reception of the message from the PGW. Since no user plane resource
is required to be established, parameters in the Create Session Response
message can be set as follows: the Serving GW Address for User Plane can
be set to 0.0.0.0, the Serving GW TEID for S1-U User Plane can be set to
0, etc., and a repeated description thereof will be omitted here. As can
be appreciated, the MME can update bearer information in a context of the
UE according to such information.

[0114] Operation 307, the MME transmits to an eNB an Attach Accept message
carrying an indicator of a null resource corresponding to the user
equipment; and

[0115] Operation 308, the eNB allocates no user plane resource to the UE
according to the indicator of a null resource and transmits an Attach
Complete message to the MME.

[0116] In this embodiment, it is not necessary to perform the operation of
updating a bearer of the attached-to network because no bearer is
established for the UE.

[0117] In a preferred embodiment of the invention, the method for saving a
network resource may further include:

[0118] Operation C1, the MME makes a record corresponding to bearer
allocation to the user equipment in the context of the UE upon reception
of an Update Location Request message from an HSS;

[0119] Operation C2, the old MME returns the corresponding context of the
UE upon reception of a Context Request message of the UE from a new MME;
and

[0120] Operation C3, the new MME determines from the corresponding record
in the context of the UE that the old MME establishes no bearer for the
UE although the old MME establishes the context of a PDN connection for
the UE and then can skip a procedure of updating a PDN bearer as in the
first scheme or perform a procedure of updating a PDN bearer as in the
second scheme but using a null resource as in the scheme while performing
the procedure.

[0121] It shall be noted that this preferred embodiment will not be
limited to the third embodiment but can be applicable to network
attachment and TAU procedures in any case that a PDN is established but
no bearer is establish for the UE. Furthermore the new MME can perform
the PDN connection procedure as in the operation 303 to the operation
306.

[0122] Referring to FIG. 4 illustrating a flow chart of a fourth
embodiment of a method for saving a network resource according to the
invention, the method may particularly include:

[0123] Operation 401, an Attach Request message carrying a newly added APN
Name is transmitted from a UE to a network;

[0124] An APN shall be carried in the Attach Request message transmitted
from the UE to the network to notify the network of a specific PDN to
which a PDN connection is to be established. In this embodiment, a
special APN is newly added and specially encoded. Thus when an MTC
terminal has the characteristic of small data, an MME can know from the
newly added special APN that the terminal has the characteristic of small
data.

[0125] Operation 402, an MME knows from the value of the APN Name that the
UE has characteristic of small data transmission upon reception of the
Attach Request message;

[0126] Operation 403, the MME skips the operation of a PDN connection in
the existing network attachment procedure upon reception of an Update
Location Request transmitted from an HSS;

[0127] Operation 404, the MME transmits to an eNB an Attach Accept message
carrying an indicator of a null resource corresponding to the user
equipment; and

[0128] Operation 405, the eNB transmits an Attach Complete message to the
MME.

[0129] Referring to FIG. 5 illustrating a flow chart of a fifth embodiment
of a method for saving network, the method may particularly include:

[0130] Operation 501, an Attach Request message without any PDN connection
establishment request message is transmitted from a UE to a network;

[0131] Operation 502, an MME determines from the absence of a PDN
connection establishment request message that the UE has the
characteristic of small data transmission upon reception of the Attach
Request message;

[0132] Operation 503, the MME skips the operation of a PDN connection in
the existing network attachment procedure upon reception of an Update
Location Request transmitted from an HSS;

[0133] Operation 504, the MME transmits to an eNB an Attach Accept message
carrying an indicator of a null resource corresponding to the user
equipment; and

[0134] Operation 505, the eNB transmits an Attach Complete message to the
MME.

[0135] Based upon the same inventive idea, there are further provided in
embodiments of the invention an apparatus for saving a network resource,
a Serving Gateway (SGW), a Packet Data Gateway (PGW) and an evolved Node
B, and since these apparatuses address the problem under a similar
principle to the method for saving a network resource, reference can be
made to the implementations of the method for implementations of these
apparatuses, and a repeated description thereof will be omitted here.

[0136] An embodiment of the invention provides an apparatus for saving a
network resource, which includes:

[0137] an obtaining module configured to determine that a user equipment
has the characteristic of small data transmission; and

[0138] a bearer allocating module configured to allocate no user plane
resource to the user equipment with the characteristic of small data
transmission in a network attachment procedure;

[0139] Furthermore the apparatus for saving a network resource further
includes:

[0140] a null resource indicator carrying module configured to transmit a
message carrying an indicator of a null resource for the user equipment
to an eNB to instruct the eNB not to allocate any user plane resource to
the user equipment.

[0141] Furthermore the apparatus for saving a network resource further
includes:

[0142] a recording module configured to make a record corresponding to
bearer allocation to the user equipment in a context of the user
equipment upon reception of an Update Location Request message from an
HSS; and

[0143] an updating module configured to transmit the context of the user
equipment to a new

[0144] MME so that the new MME performs PDN connection and Tracking Area
Update (TAU) procedures according to the context of the user equipment.

[0145] Preferably the apparatus for saving a network resource is a
Mobility Management Entity (MME).

[0146] An embodiment of the invention further provides a Serving Gateway
(SGW) including:

[0147] an indicator receiving module configured to receive an indicator,
of no bearer being required to be established, transmitted from a
Mobility Management Entity (MME) for a user equipment with the
characteristic of small data transmission; and

[0148] an allocation instructing module configured to allocate a null
resource to a Packet Data Network (PDN) connection and to transmit a
Create Session Request message, carrying the indicator of no bearer being
required to be established, to a Packet Data Gateway (PGW) to instruct
the PGW to allocate a null resource to the PDN connection.

[0149] An embodiment of the invention further provides a Packet Data
Gateway (PGW) including:

[0150] an indicator receiving module configured to receive an indicator,
of no bearer being required to be established, transmitted from a Serving
Gateway (SGW) for a user equipment with the characteristic of small data
transmission; and

[0151] a null resource allocating module configured to allocate a null
resource to a Packet Data Network (PDN) connection and to return a Create
Session Response message to the SGW.

[0152] An embodiment of the invention further provides an evolved Node B
including:

[0153] an indicator receiving module configured to receive an indicator of
a null resource transmitted from a Mobility Management Entity (MME) for a
user equipment with the characteristic of small data transmission; and

[0155] In correspondence to the foregoing embodiments of the method, the
invention further discloses a system for saving a network resource, and
referring to FIG. 6, the system may particularly includes:

[0156] an obtaining module 601 configured to obtain the characteristic of
small data transmission of a user equipment; and

[0157] a bearer allocating module 602 configured to allocate no user plane
resource to the user equipment with the characteristic of small data
transmission in a network attachment procedure.

[0158] The invention may provide the following two design schemes for the
bearer allocating module 602:

[0159] First Scheme

[0160] A first bearer allocating sub-module D1 can be designed which is
configured to establish no PDN connection for the user equipment with the
characteristic of small data transmission in the network attachment
procedure.

[0161] Second Scheme

[0162] A second bearer allocating sub-module D2 can be designed which is
configured to establish for the user equipment a PDN connection to which
no user plane resource is required to be allocated.

[0163] Specifically the second bearer allocating sub-module D2 may further
include:

[0164] a bearer indicator carrying unit D21 configured to carry an
indicator of no bearer being required to be established in a Create
Session Request message transmitted from a mobility management entity;
and

[0165] an allocating unit D22 configured to allocate a null resource to
the PDN connection according to the indicator of no bearer being required
to be established;

[0166] Preferably in an embodiment of the invention, the allocating unit
D22 may further include:

[0167] a transmitting sub-unit D221 configured to transmit a corresponding
Create Session Request message to a PGW while carrying the indicator of
no bearer being required to be established in the message according to
the indicator of no bearer being required to be established;

[0168] a first returning sub-unit D222 configured to return a
corresponding Create Session Response message to a SGW according to the
Create Session Request message; and

[0169] a second returning sub-unit D223 configured to return a
corresponding Create Session Response message to the MME according to the
Create Session Response message from the PGW.

[0170] The invention can provide the following design schemes for the
obtaining module 601:

[0171] Scheme A

[0172] A first obtaining sub-module E1 can be designed in the obtaining
module 601 to be configured to obtain the corresponding characteristic of
small data transmission from a request of the user equipment;

[0173] Preferably the first obtaining sub-module E1 may further include:

[0174] an indicator carrying unit E11 configured to carry an indicator of
small data transmission in an Attach Request message transmitted from the
user equipment; and

[0175] a knowing unit E12 configured to know from the indicator of small
data transmission that the user equipment has the characteristic of small
data transmission.

[0176] Preferably in an embodiment of the invention, the indicator of
small data transmission can include any one or combination of the
following information elements: a newly added EPS Attach Type, a newly
added Request Type or a newly added Access Point Name; or

[0177] The Attach Request can be indicated implicitly as an Attach Request
for small data transmission by including no PDN connection establishment
request message in the Attach Request message.

[0178] Scheme B

[0179] A second obtaining sub-module E2 can be designed which is
configured to know from user subscription data that the user equipment
has subscribed for the characteristic of small data transmission.

[0180] Since the first bearer allocating sub-module D1 establishes no PDN
connection and the second bearer allocating sub-module D2 allocates no
user plane resource to a PDN connection, it is not necessary to allocate
any user plane resource to the PDN connection at the side of an access
network. Thus in a preferred embodiment of the invention, the system may
further include:

[0181] a null resource indicator carrying module F configured to carry an
indicator of a null resource corresponding to the user equipment in an
Initial Context Setup Request message transmitted from the MME to an eNB.

[0182] In another preferred embodiment of the invention, the system may
further include:

[0183] a recording module G1 configured for the MME to make a record
corresponding to bearer allocation to the user equipment in a context of
the user equipment upon reception of an Update Location Request message
from an HSS; and

[0184] an updating module G2 configured to perform corresponding PDN
connection and TAU procedures of the user equipment according to the
context of the user equipment from the old MME.

[0185] Specifically the recording module may include:

[0186] a first recording unit H1 configured to create no context of any
PDN connection and preserve only mobility management context, in the
context of the UE; or

[0187] a second recording unit H2 configured to include a flag bit in the
context of the UE to indicate that no PDN connection is established for
the user equipment and to set the flag bit;

[0188] or

[0189] a third recording unit H3 configured to include a flag bit in the
context of the UE to indicate that the context of the PDN connection is
established but no bearer is established for the user equipment and to
set the flag bit.

[0190] If the updating module G2 determines from the record that the old
MME establishes no PDN connection for the UE, then the TAU and PDN
connection procedures of the UE can be skipped directly to thereby
further saving a signalling resource in the TAU procedure.

[0191] A method and system for saving a network resource according to the
invention have been introduced above in details, the principle and the
embodiments of the invention have been set forth herein in connection
with several instances, and the foregoing embodiments have been described
merely for the purpose of facilitating understanding of the inventive
method and the core idea thereof; and also those ordinarily skilled in
the art can modify the invention in the embodiments and application scope
thereof according to the idea of the invention. In summary the disclosure
of this specification shall not be construed as limiting the scope of the
invention.

[0192] The respective embodiments in this specification have been
described progressively, and each of the embodiments has been focused
upon the difference or differences thereof from the other embodiments,
and identical or similar parts between the respective embodiments can
apply across the embodiments. The embodiments of the system are
substantially the same as those of the method and thus have been
described briefly, and reference can be made to the description of the
embodiments of the method for relevant details thereof.

[0193] Those skilled in the art shall appreciate that the embodiments of
the invention can be embodied as a method, a system or a computer program
product. Therefore the invention can be embodied in the form of an
all-hardware embodiment, an all-software embodiment or an embodiment of
software and hardware in combination. Furthermore the invention can be
embodied in the form of a computer program product embodied in one or
more computer useable storage mediums (including but not limited to a
disk memory, a CD-ROM, an optical memory, etc.) in which computer useable
program codes are contained.

[0194] The invention has been described in a flow chart and/or a block
diagram of the method, the device (system) and the computer program
product according to the embodiments of the invention. It shall be
appreciated that respective flows and/or blocks in the flow chart and/or
the block diagram and combinations of the flows and/or the blocks in the
flow chart and/or the block diagram can be embodied in computer program
instructions. These computer program instructions can be loaded onto a
general-purpose computer, a specific-purpose computer, an embedded
processor or a processor of another programmable data processing device
to produce a machine so that the instructions executed on the computer or
the processor of the other programmable data processing device create
means for performing the functions specified in the flow(s) of the flow
chart and/or the block(s) of the block diagram.

[0195] These computer program instructions can also be stored into a
computer readable memory capable of directing the computer or the other
programmable data processing device to operate in a specific manner so
that the instructions stored in the computer readable memory create an
article of manufacture including instruction means which perform the
functions specified in the flow(s) of the flow chart and/or the block(s)
of the block diagram.

[0196] These computer program instructions can also be loaded onto the
computer or the other programmable data processing device so that a
series of operational steps are performed on the computer or the other
programmable data processing device to create a computer implemented
process so that the instructions executed on the computer or the other
programmable device provide steps for performing the functions specified
in the flow(s) of the flow chart and/or the block(s) of the block
diagram.

[0197] Although the preferred embodiments of the invention have been
described, those skilled in the art benefiting from the underlying
inventive concept can make additional modifications and variations to
these embodiments. Therefore the appended claims are intended to be
construed as encompassing the preferred embodiments and all the
modifications and variations coming into the scope of the invention.